H41 - Initiate KOER Self-Test

- Key Off.

- Scan Tool connected.

- Enter Key On Engine Running (KOER) Self-Test.

- Are an of the above HO2S codes from test step H40 present?

YES -- Go to H42. H42 - Check Fuel Pressure

NO -- The fault that produced the DTC is an intermittent. GO to Pinpoint Test Step Z1 with the following data: HO2S-11, 21, 12, 22 PIDs and list of Possible Causes. Z1 - Intermittent Test Procedure